On Monday the Civil Aviation Authority of Vietnam (CAAV) had banned incoming international flights to Hanoi's Noi Bai International Airport for a week and to HCMC’s Tan Son Nhat International Airport until June 14.
But it suddenly overturned the ban without providing any explanation.
Meanwhile, Vietnam Airlines has said it plans to trial a vaccine passport this month.
The country has recorded 4,549 Covid-19 cases since a new wave began on April 27.